said press



F. J. REICHMANN AND 1. PRESS.

TELEPHONE INSTRUMENT.

APPLICATION FILED JUNE 2|, 191B.

Patented May 24, 1921.

ll/Ir!!! I!!! VIII!!! VIIlI/Ilfll/lrllllllllfllllllllfll I III/ ries a suitably insulated spoolwinding UNITED STATES PATENT OFFICE.

FRANK J. REICHMANN AND JOHN PRESS, OF CHICAGO, ILLINOIS; SAID PRESS ASSIGNOR TO SAID REICHMANN.

TELEPHONE INSTRUMENT.

Specification of Letters Patent.

Patented May 24, 1921.

To all whom it may concern:

Be it known that we, FRANK J. Rerou- MANN and JOHN Pnnss, citizens of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a new and useful Telephone Instrument, of which the following is a specification.

Our invention relates to improvements in telephone instruments and will be fully understood from the following specification taken in connection with the accompanying drawings, which illustrate one embodiment of the invention. In these drawings, Figure 1 is a sectional View through the housing of a loud-speaking telephone receiver, constructed in accordance with our invention, this view being taken substantially on the line 1 of Fig. 2; Fig. 2 is a side elevation of the instrument, as indicated by the line 2 of Fig. 1, the casing being sectioned; Fig. 3 is a central section on the line 3 of Fig. 1; and Fig. 4 is a similar section on the line 4 of Fig. 1.

Referring more particularly to the drawings, the numeral 10 designates a metal head, which may be pressed to the form illustrated to provide a diaphragm chamber 11, in which there is mounted a mica diaphragm 12, supported between tubular rubber washers 13 in the well known manner. The front of the diaphragm chamber is closed by a metal cover 14 secured to the head 10 as by the screws shown and having a centrally threaded nipple 15 which serves for the attachment of the amplif ing horn 16 commonly used on loud-speafiin telephone receivers. The cover 14 1s pre erably flanged over the head 10 on the outside, as illustrated, being thus made to serve as a shoulder against which seats the edge of a pressed metal case 18 of cup-like form. The case 18 may be secured to the head 10 by a pin-andbayonet slot or other improved fastening of simple type.

The inner face of the head 10 has secured thereto, as by the screws 19, a modified horseshoe magnet 20, shown as made of two laminations. One pole of the magnet 20, this pole being formed by the ends of both laminations, has secured therein a ma netic metal stud 21, which extends at rig t angles to the plane of the magnet and cg;- At the other end of the magnet 20 the lower or inner lamination thereof is interrupted, as shown at 20 while the upper or outer lamination, which is of considerable length, is turned inwardly and upwardly as shown at 23; and has its extremity sheared at an angle to form a knife-edge 24 lying approximately in the plane of the upper end of the stud-core 21 which forms one polepiece of the magnet and symmetrically disposed with reference to and at right angles to a radius through the said stud. Balanced upon the knifeedge 24 and in a plane substantially parallel with the plane of the magnet 20 is an armature 25 having approximately the contour of a keystone, its broad base end resting on the knife-edge 24 and its narrower outer end lying just above the end face of the pole-piece 21, clearing the latter by a distance so small that no attempt has been made to illustrate it in the drawing. From the base of the armature 25 an integral arm 26 extends outward to the approximate center of the magnet, at which point it is connected by a rigid link 27 with the center of the diaphragm 12, the head 10 being perforated to provide for this link connection. The armature is held in contact with the knife-edge 24 and a ainst displacement longitudinally thereo by a resilient overhanging arm 28, having a relatively acute point 29, which bears in a shallow depression in the outer face of the armature and just opposite the knife-edge plvot.

Adjustment of the clearance between the end of the armature 25 and the pole-piece 21, by which adjustment the action of the diaphragm is regulated, is obtained by distortion of the upturned magnet pole 23. To effect this adjustment with the re uired degree of nicety, we have provided an a j ustment wedging screw 30 threaded in one upturned car on the head 10 and guided by a second ear upturned in the same manner. Between these points of support the screw 30 carries a conical collar 31, the angle of which is the same as that of the ma net terminal 23, as shown in Fig. 4. T e body and slotted head of the screw 30 lie within a bore and counter-bore in a molded terminal-block 32, secured to the head and serving as a means for the attachment of the binding posts of the spool-winding 22. We prefer to form an aperture in the case 18 opposite the end of the screw 30, so that adjustment of the instrument may be effected without removing the case. The required extreme range of adjustment of the knife-edge 24f lies well within the clastic limits of the magnet-steel, and by initially forming the magnet with proper relation between the upturned extremity 23 and the stud 21, the entire range of adjustment required in practice may be attained by flex ing or distorting this upturned end. The friction between the conical collar 31 and the inner face of the magnet extremity is sufficient to positively lock the screw 30 in any adjusted position.

In the operation of our improved telephone instrument the winding of the spool 22 will be connected with the sound-transmitting line in the usual way, and by the pulsations of the current in the winding the outer end of the armature 25 will be vibrated with respect to the pole-piece 21, which vibrations, slightly increased in magnitude in the particular embodiment of the invention shown, by'reason of the proportions of the lever arms of the armature, will be transmitted to the diaphragm 12 to thereby reproduce the transmitted sound. The necessary adjustments of the instrument are effected as described, by the screw 30.

While we have illustrated and described in considerable detail a preferred embodiment of our invention, it will be understood that this is illustrative only and for the purpose of making the invention more clear and that the invention is not to be regarded as limited to any of the details of construction shown or described, except in so far as they may be included within the terms of the accompanying claims, in which it is our intention to claim all novelty inherent in our invention as broadly as is permissible in view of the prior art.

What we regard as new and desire to secure by Letters Patent is:

1. In a telephone instrument, a magnet, an armature movably supported upon one pole of the magnet and extending into operative relation with the other pole thereof, and means for changing the form of the magnet to alter the relative positions of the poles.

2. In a telephone instrument, a magnet, an armature movably supported upon one pole thereof and extending into operative relation with the other pole thereof, and means for flexing the magnet to alter the relative positions of the poles.

3. In a telephone instrument, a magnet, an armature pivoted upon one pole and extending into operative relationship with the other pole, and means for flexin the magnellfi to change the relative positions of the po es.

4. In a telephone instrument, a magnet having a knife-edge pivot on one pole-piece thereof, an armature balanced on said pivot and bridging the gap between the polepieces, and means for deforming the said magnet to change the relative positions of the poles.

5. In a telephone instrument, a magnet, a knife-edge pivot forming one integral polepiece thereof, an armature balanced intermediate its length on the said pivot and having one end bridging the gap between the poles of the magnet, and means carried by the opposite end of the armature for transmitting vibrations, and means for holding said armature in contact with said knifeedge pivot.

6. In a telephone instrument, a magnet, a knife-edge pivot forming one integral polepiece thereof, an armature balanced intermediate its length on. the said pivot and having one end bridging the gap between the poles of the magnet, means carried by the opposite end of the armature for transmitting vibrations, and a spring for holding said armature in contact with said knifeedge pivot.

7. In a telephone instrument, a magnet, a knife-edge pivot forming one integral polepiece thereof, an armature balanced inter mediate its length on thesaid pivot and having one end bridging the gap between the poles of the magnet, means carried by the opposite end of the armature for transmitting vibrations, means for holding said armature in contact with said knife-edge pivot, and means for adjusting the. gap between the armature and the opposing pole of the magnet.

8. In a telephone instrument, a horseshoe magnet having out-turned pole-pieces, an armature balanced intermediate its length on one of said pole-pieces and upon one end bridging the gap between the pole-pieces,

means attached to the opposite end of the armature for transmitting vibrations, and means for deforming the said magnet to change the relative positions of the polepieces.

9. A telephone instrument comprising a generally disk-like head, a modified horseshoe magnet secured to the said head and lying parallel therewith, out-turned polepieces carried by said magnet, the gap between said pole-pieces lying in a line generally radial with respect to the head, and

an armature pivoted upon the inner polepiece at a point intermediate its length and extending radially outward to bridge the gap between the pole-pieces and radially inward to the approximate center of the head, and means carried by the inner end of the armature for transmitting vibrations.

10. In a telephone instrument, a magnet having a fixed pole-piece and an adjustable pole-piece, and an armature pivoted upon the adjustable pole-piece and extending into operative relation with the fixed pole-piece.

11. In a telephone instrument, a horseshoe magnet having out-turned pole-pieces, one of which is fixed and the other of which is adjustable toward and away from the plane of the magnet, and an armature mounted upon one of said pole-pieces and bridging the gap between them.

12. In a telephone instrument, a horseshoe magnet having out-turned pole-pieces, one of which is fixed and the other of which is adjustable toward and away from the plane of the magnet, and an armature pivoted upon the adjustable pole-piece and bridging the gap between the poles.

13. In a telephone instrument, a horseshoe magnet having out-turned pole-pieces, one of which is fixed and the other of which is adjustable toward and away from the plane of the magnet. a knife-edge pivot formed on the adjustable pole-piece, and an armature carried by the said pivot and bridging the gap between the pole-pieces.

14. In a telephone instrument, a magnet, an armature balanced on said magnet by a knife-edge pivot and means bearing upon the opposite side of the armature for holdirg it resiliently in contact with the knifee ge.

15. In a telephone instrument, a magnet having a knife-edge pivot on one pole-piece thereof, an armature balanced on said pivot and a resilient member having a pin-andsocket bearing with the opposite side of the armature for holding the latter in engagement with the knife-edge pivot.

16. In a telephone instrument, a disk-like head, a horseshoe magnet secured to the said head in a plane parallel therewith, one end of said magnet being flexible, and an adjustable wedge engaging the said flexible end for flexing the same.

17. In a telephone instrument, a horseshoe magnet having one out-turned polepiece and having the other pole-piece bent upwardly at an angle so that its extremity lies in the plane of the first pole-piece, a movable armature bridging the said poles, and means for flexing the bent pole-piece toward and away from the plane of the magnet.

18. In a telephone instrument, a generally disk-like head, a horseshoe magnet secured to the back of the said head in a plane parallel therewith, out-turned pole-pieces carried by the magnet, a movable armature bridging the gap between the said polepieces and a wedging-screw secured to the said head and engaging one of the said polepieces to flex the latter toward and away from the plane of the magnet.

19. In a telephone instrument, a disk-like head, a horseshoe magnet with one of its poles secured to said head. the other pole being flexible, and means for flexing the flexible pole.

20. In a telephone instrument. a disk-like head, a horseshoe magnet in a plane parallel with said head with one of its poles secured thereto. the other pole being flexible, and means for flexing the flexible pole.

21. In a telephone instrument, a disk-like head. a horseshoe magnet in a plane parallel with said head with one of its poles secured thereto. the other pole being flexible. and an adjustable wedge engaging the said flexible pole for flexin the same.

FTRANK J. REICHMANN. JOHN PRESS. 

